The present invention relates generally to systems for respiratory therapy, particularly to ventilator systems that includes heat and moisture exchanger (HME) media or heat and moisture exchanger (HME) media in the respiratory path and also provides the additional capability of administering aerosol medication to a patient effectively without interrupting the respiratory path.
The closest prior art is believed to be illustrated in FIG. 1, in which a conventional heat and moisture exchanger (HME) 1 has a port 2 connected to a port 3 of a bypass device 4. Bypass device 4 is marketed by DHD Healthcare of Watsonville, N.Y. under the trademark CIRCUVENT. Heat and moisture exchanger 1 has a port 5 connected to port 6 of a Y connector 10 having a connector which is coupled to an endotracheal tube (not shown) in the patient. Bypass device 4 includes another port 7 connected to one end of a flexible bypass tube 8 having its other end connected to another port 9 of Y connector 10. Bypass device 4 has a port 11 connected by suitable tube to a ventilator (not shown). A rotatable control ring 13 can be adjusted so that gas received through port 11 from the ventilator is selectively routed through either heat and moisture exchanger 1 or bypass tube 8. If aerosol medication is introduced into the respiratory path upstream from port 11, then control ring 13 is turned to direct the gas carrying the aerosol medication around heat and moisture exchanger 1 through bypass tube 8. This prevents the aerosol droplets/particles from impacting on the media of heat and moisture exchanger 1 (and any filter material that may be provided with it).
The bypass tube 8 of the assembly shown in FIG. 1 has a large volume of “dead space” which results in a relatively large amount of previously exhaled air being re-breathed by the patient. This reduces the amount of oxygen received by the patient's lungs and is always undesirable, and in some instances can be dangerous, especially for a critically ill infant being supported on a ventilator. The assembly shown FIG. 1 is bulky, relatively heavy, and tends to be leaky.
The cost of a typical HME or HMEF element 1 or an HCH element can be in the range from approximately $1.50 to $5.00, and the bypass device 4 can cost from approximately $3.50 to $7.00.
Thus, there is an unmet need for a device and method for selectively conducting a stream of air produced by a ventilator through a moisturizing medium in the device or internally bypassing the moisturizing medium to prevent aerosolized medication that has been introduced into the stream from contacting the moisturizing medium.
There also is an unmet need for such a device and method that reduces the cost of selectively conducting a stream of air produced by a ventilator through a moisturizing medium in the device or internally bypassing the moisturizing medium to prevent aerosolized medication that has been introduced into the stream from contacting the moisturizing medium.
There also is an unmet need for such a device and method that reduces the cost of selectively conducting a stream of air produced by a ventilator through a moisturizing medium in the device or internally bypassing the moisturizing medium to prevent aerosolized medication that has been introduced into the stream from contacting the moisturizing medium, wherein the device and method also reduce the risk of infection to the patient.
There also is an unmet need for such a device and method that reduces the cost of selectively conducting a stream of air produced by a ventilator through a moisturizing medium in the device or internally bypassing the moisturizing medium to prevent aerosolized medication that has been introduced into the stream from contacting the moisturizing medium, wherein the device and method also reduce the risk to the patient associated with a large volume of a “dead space” in the respiratory path.